This invention relates to granular detergent compositions which are capable of providing superior performance during conventional textile laundering and cleaning operations. In more detail, the compositions of this invention contain as essential components an organic surface-active agent, a water-insoluble aluminosilicate ion exchange material and a minor amount of an alkali oxide silicate solid.
The use of water-insoluble synthetic aluminosilicates in detergent compositions in combination with organic surface-active agents is described in copending U.S. patent application Ser. No. 359,293, filed Mar. 11, 1974, titled "Detergent Composition", inventors Corkill, et al. The compositions of Corkill et al., though excellent performers, can require the presence of a metal corrosion inhibitor to protect the washing machine and also an agent to render the granules more crisp and accordingly to confer better free-flowing characteristics. In conventional heavyduty detergent compositions, satisfactory corrosion inhibition and granule crispness are obtained through the incorporation of sodium silicate in an amount from about 6% to about 20%. Although the compositions of Corkill et al. will provide acceptable cleaning performance, the combination of organic surfactants, water-insoluble aluminosilicates and silicate in the normal levels can present deposition problems which can adversely affect the appearance of the textile. Hence, under certain circumstances, it can be desirable to avoid these appearance shortcomings without resorting to exotic and commercially unattractive inhibitors and crispness agents.
It is known that laundry compositions function more efficiently in soft water than in water containing significant amounts of dissolved "hardness" cations such as calcium ion, magnesium ion and the like. Zeolites or other cation exchange materials were frequently used to pre-soften water. Such pre-softening procedures require an additional expense to the user occasioned by the need to purchase the softener appliance.
Another means whereby fabrics can be optimally laundered under hard water conditions involves the use of water-soluble builder salts and/or chelators to sequester the undesirable hardness cations and to effectively remove them from interaction with the fabrics and detergent materials in the laundering liquor. However, the use of such water-soluble builders necessarily introduces into the water supply certain materials which, in improperly treated sewerage effluents, may be undesirable. Accordingly, a means for providing water-softening builders in detergent compositions without the need for soluble builder additives is desirable.
A variety x methods have been suggested for providing builder and water-softening action concurrently with the deterging cycle of a home laundering operation, but without the need for water-soluble detergent additives. One such method employs a phosphorylated cloth which can be added to the laundry bath to sequester hardness ions and which can be removed after each laundering; see U.S. Pat. No. 3,424,545.
The use of certain clay minerals to adsorb hardness ions from laundering liquors has also been suggested; see, for example, Rao, in Soap Vol. 3 No. 3 pp. 3-13 (1950); Schwarz, et al. "Surface Active Agents and Detergents", Vol. 2, p, 297 et seq. (1966).
Zeolites, especially naturally-occurring aluminosilicate zeolites, have been suggested for use in washing compositions; see U.S. Pat. No. 2,213,641; also U.S. Pat. No. 2,264,103.
Various aluminosilicates have been suggested for use as adjuncts to and with detergent compositions; see, for example, U.S. Pat. Nos. 923,850; 1,419,625; and British Pat. Nos. 339,355; 461,103; 462,591; and 522,097.
From the foregoing it is seen that a variety of methods have been heretofore employed to remove hardness cations from aqueous laundering systems concurrently with the deterging cycle of a home laundry operation. However, these methods have not met with general success, primarily due to the inability of the art-disclosed materials to rapidly and efficiently reduce the free polyvalent metal ion content of the aqueous laundering liquor to acceptable hardness levels. To be truly useful in laundry detergent compositions, an ion exchange material must have sufficient cation exchange capacity to significantly decrease the hardness of the laundry bath without requiring excessive amounts of the ion exchanger. Moreover, the ion exchange material must act rapidly, i.e., it must reduce the cation hardness in an aqueous laundry bath to an acceptable level within the limited time (ca. 10-12 minutes) available during the deterging cycle of a home laundering operation. Optimally, effective ion exchange materials should be capable of reducing calcium hardness to about 1 to 2 grains per gallon within the first 1 to 3 minutes of the deterging cycle. Finally, useful cation exchange builders are desirably substantially water-insoluble, inorganic materials which present little or no ecological problems in sewage.
It is an object of this invention to provide detergent compositions containing water-insoluble aluminosilicate ion exchange materials which are capable of providing superior performance, particularly textile appearance benefits.
It is a further object of this invention to provide detergent compositions containing water-insoluble aluminosilicates having effective corrosion inhibition and granule crispness characteristics.
The above and other objects are now met as will be seen from the following disclosure.